I have had several Rabbit FC's on several multirotors and have an observation. My last Rabbit was on a spider quad and mounted on the top in the clear from other structures and GPS and other functions seemed to work OK. I moved the FC/motors/ESC's to a 450 flamewheel quad on the bottom level and GPS functions did not work. The LF GUI showed GPS fix and compass
and baro and sonar function as normal ,but nothing worked well except stabilize flight. I moved it all back to the spider quad with devices more separated by distance and now working again. Maybe the Rabbit is sensitive to magnetic fields ? Component placement effects performance. That may be why some have good luck with the Rabbit and others do not.

You got it, its common sense really the magnetometer is sensitive to magnetic fields.
Also the GPS should always be mounted away from the FC & anything else that could affect it, ideally at least 10cm (3") above.

I have been following this thread since I bought my Rabbit. It is the original one with the 'one hole' baromter, magnatometer, sonar and a Crius GPS module. I am running the latest software and it flies great on an X525 frame. However I cannot seem to find a definitive answer to the following questions:-

1) If I engage position hold do I also need to engage height hold as well?
2) When I engage 'care free' does the Rabbit take it's reference as the take off orientation or the orientation when 'care free'was engaged e.g. I loose orientation of the quad and it is in front of me. If i engage 'care free' and pull back on the stick will it always return back to me?
3) Can I engage position hold and care free at the same time?

1) If I engage position hold do I also need to engage height hold as well?

Nope, no need to have height hold checked with position hold or go home. I have height hold on a separate switch and not bound to pos hold and it works just fine with or without it enabled.

2) When I engage 'care free' does the Rabbit take it's reference as the take off orientation or the orientation when 'care free'was engaged e.g. I loose orientation of the quad and it is in front of me. If i engage 'care free' and pull back on the stick will it always return back to me?

It always bases it reference on the orientation the moment you arm the copter. If you land, disarm and rearm then that orientation becomes the new reference for 'forward'. Something to remember if you've enabled auto-disarm timeout and land without paying attention to the orientation and then re-arm.

You can engage and disengage CF as many times as you want during flight and it will not reset or change the reference heading, regardless of which way the copter's facing at the time CF is enabled or disabled. I've flown out many times, pointed my copter in a random heading and engaged CF; it always came back when I pulled back on the stick (assuming I had armed it while facing forward at takeoff). If it's not working this way for you, then you either have stray magnetic fields, haven't calibrated the compass properly, are using pre-1.210 firmware with poor CF code, or have a bad magnetometer. With that said you need to account for wind. If you have a cross wind then pulling back on the stick in CF mode will cause the copter to come back towards you but the wind will also carry it side ways.

*CF behavior is based on magnetic poles and assumes the copter is somewhere out in 'front' of you. If you're the type who likes to fly high up with the copter above you; when it inevitably gets behind you, pulling back on the stick will of course just make it go further away. Long story short...If you rely on CF to save you're bacon then always fly with the copter well out in front.

3) Can I engage position hold and care free at the same time?

Hmm, haven't tried that one but I would think you could. I did try flying around with both care free and go home enabled. It worked fine at first but then after a while started behaving strangely, so I figured I was causing the poor Rabbit to divide by 0 and stopped.

I wish my micro Hubsan X4 had Care Free mode. I fly that thing far out and 100% of the time without bothering to track orientation. In no wind it's easy enough, but today at the beach I had a few tense moments trying to detect the direction it was heading with a brisk wind trying to make off with it. In those cases I let it drop out of the sky till it gets low to the ground so wind isn't as strong, and then try to re-orientate or just set down and go get it.

// there's less shame in walking over to get a copter after having lost orientation, than there is in getting it out of a tree or off someone's roof.

// there's less shame in walking over to get a copter after having lost orientation, than there is in having to get it out of a tree or off someone's roof.

Your a brave man, I fly my X4 indoors all the time but outdoors; well its OK in the yard where there are high walls surrounding it but the couple of times I took it out to the field; first time a seagull attacked it & the second it took off (it was windy) for the jetstream.